(a) If, in the preparation of the final work plan, it is determined by the board that the location and character of the works of improvement are so varied that it would be impractical to let contracts on all of them in the same year or if funds would not be available for all of them in the same year, the final work plan may be segregated and divided into one (1) or more units of construction constituting any work or group of works proposed in the final work plan which can be constructed and operated as a feasible unit alone and which can also be operated economically and in conjunction with other proposed works in the plan.
(b) The final work plan shall indicate the area included in each unit of construction and establish each such area as a separate construction area, set forth a percentage or portion of the total project costs allocated to each construction area, and delineate the lands in each construction area which, on the basis of preliminary estimates, would derive some benefits from the works of improvement to be installed therein.
(c) Each construction area shall be appropriately identified by name and number, such as “Construction Area No. ”
(d) The determination of the board that the works are approved and proposed in the final work plan, even though divided into units of construction, do not lack unity or singleness of purpose and that the works in each unit of construction confer some benefit on the lands therein shall be final and conclusive.
(e) The board of commissioners shall have authority to let contracts for carrying out the works of improvement on a construction area basis and to borrow money and issue notes or bonds and assess benefits and damages on a construction area basis.
(f) A separate assessment book shall be prepared and maintained for each construction area.
(g) The tax levied to secure and repay notes or bonds shall be limited to and be a lien only on the lands located within each construction area found to be benefited by the works installed at the construction area, and that fact shall be indicated on the face of the bonds or notes.
(h) All published notices with respect to the assessment of benefits and damages and the borrowing of money and issuance of notes and bonds shall list the lands according to the construction area in which they are located.